My firefox visual hacks

userChrome.css

/* Hide horizontal tabs at the top of the window #1349 */
#TabsToolbar {
    visibility: collapse !important;
}

/* For only Tree Style Tab sidebar #1397 */
#sidebar-box[sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"] #sidebar-header {
    display: none !important;
}


/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * Hide tabs on Linux, Windows, any with titlebar.
 * Doesn't work right with MacOS, use the other one instead
 *
 * Contributor(s): Isaac-Newt
 */

#TabsToolbar {
  visibility: collapse !important;
}